Internal-combustion engine



-March 6, 1928.

K. EIERMANN INTERNAL COMBUSTION ENGINE Filed April 14." 1924 1A A a m Patented Mar. 6, 1928.

UNITED STATES PATENT OFFICE.

KARL EIERMANN, F MUNICB, GERMANY, ASSIGNOR TO THE FIRM: COLD-DIESEL- MOTORENGESELLSCHAFT M. B. IL, 0] MUNICH, GERMANY.

INTERNAL-COMBUSTION ENGINE.

Application filed April 14, 1924, Serial No. 706,700, and in Germany April 18, 1983.

This invention relates to internal combustion engines of the kind working on the in jection principle and its main object is the provision of means whereby the process of ignition and combustion may be so controlled or timed as to enable an increased efiiciency of the engine and a reduced consumption of fuel to be obtained.

Another object of the invention, for the aforesaid purpose, is to greatly improve the turbulence of the air compressed within the working cylinder and to lengthen, in its initial stage, the period in which the charge is fired and consumed, so as to produce a comparatively slow combustion in the cylinder and to thus obtain a working diagram which will very closely resemble that of a constant pressure. engine.

With these and other objects in view the invention mainly consists in the arrangement of a tubular projection or, as it may be termed, a timing sleeve, upon the piston adapted to closely engage with the reduced neck of the ignition chamber and having circumferentially arranged perforations near its lower end through which the ignition, after having been started in the ignition chamber, can at first only gradually be propagated into the compression chamber of the working cylinder, thus causing a retarded combustion within the said cylinder until such moment at which the said sleeve has left the ignition chamber neck. when the full volume of burning gases will be free to enter the cylinder and complete the combustion in a more spontaneous manner.

The accompanying sheet of drawings di'agrammatically illustrates the invention by way of example. All figures shown represent similar vertical sections through part of the engine cylinder, the cylinder head, and the piston with the timing sleeve aplied.

P Fig. 1 shows the piston nearing the end of its compression stroke.

Fig. 2 shows the end position of the compression stroke in which ignition chamber and engine cylinder only communicate by means of the circumferential perforations in the timing sleeve.

Fig. 3 is a view similar to Fig. 2 and shows the said perforations arranged slightly higher up on the sleeve so as to completely close the cylinder from the ignition chamher at the point of highest compression.

In all these figures (1 represents the engine cylinder, 6 the cylinder cover with its ignition chamber 0. d is an inset nozzle or liner which, however, is immaterial to the invention, as the neck of the ignition chamber itself may be reduced to the same diameter and to thus serve the same purpose. The piston e has a central tubular projection or sleeve f which is provided with perforations 9 near its lower end and which exactly correspond to the clear diameter of the piece d. .It is advisable to slant the engaging ends of the sleeve 7 and of the ignition chamber neck in order to ensure a proper co-operation under all circumstances.

The compression space of the working cylinder is preferably of wedge-shaped cross section which, in the dead centre position of the piston according to Fig. 2. gradually passes into the perforations g. This position illustrates the moment of highest turbulence in the engine cylinder and in the ignition chamber, and it is this moment at which the fuel is injected in the usual manner and at which ignition begins to take place in-the ignition chamber also in the usual manner by the heat of the highly compressed air. But it is only by the small perforations that the ignition can then proceed into the engine cylinder until the sleeve has gntirely left the neck of the ignition cham- With some kinds of fuel or under some particular working conditions of the engine it may be found useful temporarily to sep arate the ignition chamber from the engine cylinder at the moment of fuel injection, and in such cases the perforations 9 may be placed slightly higher up on the sleeve, so that in the upper dead centre position of the piston they will be covered by the nozzle 03, or the ignition chamber neck respectively. This position is shown in Fig. 3, and it will be evident, that in this way the progress of ignition and combustion may be retarded further still and the constant pressure action of the engine still more improved.

The height and the diameter of the sleeve 7' and the size of the perforations g are, of course, immaterial to the invention; they may in each case be chosen to suit either the mation. This formation corresponds to the.

- outwardly broadening spray of fuel or gas passing through the perforations g and enables a perfect mixing of the fuel particles with the air in the broader portion of this compression space. It must be understood, however, that the 1 compression space may have an other known or convenient formation wit out in the leastdeparting from the spirit of the invention as laid down in the claim at the end of this specification.

The perforations in the sleeve f may be arranged radially or tangentially; in the latter case the turbulence in the compression chamber will receive a spiral impulse which would have a favourable influence on the combustion which, however, is not new per se.

What I claim is An 'nternal combustion engine for practicing the method hereinbefore described, comprising in combination, a cylinder having an ignition chamber, areduced neck for sald ignition chamber, a working piston reciprocating in the engine cylinder, a sleeve member on the top of the piston in intimate sliding contact with the neck ofthe ignition chamber when the piston approaches its up: per dead center position, and perforations at the base of the said sleeve member providing the only means of communication between the ignition chamber and the compression chamber of the cylinder upon the projection of said sleeve member into the neck of the ignition chamber.

In witness whereof I afiix my signature. KARL EIERMANN. 

